Process of regulating catalysis.



STATES PATENT onFIcE,

- nimon a. smash am mm or new YORK, N. 1;, ASSIGNOBB zro can-moan nnvnnorrmn'r coin-m, a CORPORATION-F name.

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12,308,777. specim n-armamen "PatentedJ-ulys, 1919. Ho Drawing a ueauon'meda ms, 1e12, sci-1010114922. Renewed Deceniher'13, 191s. Serial Ho.

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To, all whom it may concern:

,jecte to the reaction of catalysts under temperature-controlledconditions and in the presence of a "sufficient amount of a diluent 1 gas or vapor, inert under the conditions "of reaction, to slow down the reaction suffi- -ciently to stopjat a desired point or stage,

a point short of that to which such reaction would naturally proceed; and it'more particularly comprises a method of forming ethylene from acetylene wherein such acetylene is admixed with the proper amount of. hydrogen, or gas containing the same, the admixture diluted with a gas, such as carbon .dioxid, inert under the;reaction conditions 1 and in amount suflicient to slow down the hydrogenation and other reactions to a controllable degree, and the admixture is ledover azcatalyst', such as nickel, cobalt, iron, copper, platinum, palladium, etc., under tem rature=-controlled conditions until formation of ethylene is complete; all as more 8 5 fully hereinafter set forth and as claimed.

is well known, many bodies, such as platinum and palladium, have the power of condensing and adsorbing various gases and, effecting catalytic reactions therewith. In the-Sabatier & Senderens synthesis .re-

cently reduced nickel, cobalt, iron or copper isused forthe same-purpose; nickel being the most reactive. Many carbon compounds may be caused to add hydrogen OrgSllbStitllie hydrogen for oxygen by-- assing a mixture of the compound with by rogen over nick'el, "etc, as in convertingbenzol to cyclohexaneor carbon dioxid to methane, With unsaturated hydrocarbons however the reaction,

and particularly with nickel, is apt to go too far. It is, for example, diflicult to shorthydrogenate acetylene in' 'the presence of these, catalytics to obtain ethylene in any yield, the reaction tending to go forward to completion and produce ethane to the extent posible with the amount of hydrogen present with condensation and polymeri-' Such ethylene zation of residual acetylene. as is produced tends to condense also for the most part to produce oils.

In the present invention the reaction is restrained and' controlled by the simple expedient of diluting the reacting gases with an inert gas or vapor} a gas or vapor other than those resultin from the action or used in such action. With a suitabledilution by gases or vapors inert in the reaction taking place and with a proper temperature control of the catalyst, a wide variety of useful chemical reactions can .be initiated and smoothly conducted to the desired stage of completion. The present invention however will be hereinafter more specifically dcscribed in its application to the manufacture of ethylene from acetylene.

Acetylene in contact with reduced nickel at common temperatures,

and in contact with iron, copper and cobalt at somewhat higher temperatures undergoes polymerization or decomposition, or commonly, both, yielding indefinite proportions of solid, liquid and gaseous more or less free carbon. It may be wholly decomposed into carbon and hydrogen. With copper a peculiar corky carbonaceous'body, cuprene," may be 0 tained. On -mixing hydrogen with-acety-vlene and passing over t e catalysts, thelreactions and the evolution of heat become still hydrocarbons with, usually, I

more energetic, both hydrogenating and breaking. down actions occurrin simultaneously. With an excem of hy rogen, it" is not diflicult to obtain ethane with a fairly yield? but with merely enough hydrogen'to form ethylene, the yield of-the latter ing localized spreads out over the tube and.

is not great, much of'the acetylene being converted into other products while the hydrogen mostly goes to form ethane as before. On passing a mixture of equal volumes of acetylene and hydrogen into a tube containing nickel and palladium on petroleum coke (as a carrier to increase the surface) an energetic reaction takes place, beginningv becomes smoothand regular with the production of good yields of ethylene. With,

say, a passage over18 inches of catalyst the reaction may be complete.

Using carbon dioxid or products of combustion as the diluent, the ethylene formed may be scrubbed out-and recovered with the use of wash oil by passing the eflluent gases through a tower against a current of oil of turpentine, a suitable-petroleum oil, or the like, the charged oil being subsequently heated to revaporize the" ethylene and recover such' oil -for re-use. Pressure and vacuum may be used in charging and discharging. Scrubbing in this manner, the washed diluent gas may be returned for re-use, or the ethylene, in making ether, etc., may be absorbed in a liquid, such as sulfuricacid, with which it reactschemically. The diluted ethylene may be admixed with chlorin to form ethylene dichlorid (Dutch liquid), the diluent gas acting usefully in restraining the violence of the action and preventing the formation of other chlorination products. After condensing out the dichlorld, the diluent gas may be returned for use anew. With carbon dioxid 50.

as a diluent, this can be absorbedout by lime to give. pure ethylene, or it can be removed and recovered by liquefaction.

r The catalytic operation may be performed in -a tube having means for controlling the temperature; and the catalyst may be used as a layer or train of active metal, or, and preferably, be carried on a carrier such as asbestos, kioselguhr, pumice stone, etc., to extend the area of contact with the gasf Petroleum coke is a particularly good car: riersince'in addition to good physical properties for this purpose it has the advantage of being nearly ashless enabling a good by simply burning the catalyst carrying mass, and as it is a relatively good.con-

'ductor 0t heat, it keeps thetemperature of the reactive particles of catalyst equalized,

restraining undue heating of the same. In takmg advantage of this property, it is better to have the charge of catalyst on the coke relatively small as this gives the catalyst as isolated particles.

Another expedient which may be used to good advantage is to have the catalyst occur in heat-conducting relationship to a body of a good heat-conductive metal, such as copper, such body, in turn, being in heattransmittingrelationship to means, such as a body of hot or cold fluid, for controlling the temperature. For example, a rod or wlre of copper may have part of its body extending 'into a reaction chamber while another part extends into a heat-controlling acket. On the portion extending into the reaction chamber may be carried a layer of active catalyst such as reduced nickel. Such a layer may be produced by painting the desired amount of surface with, for 1n-.

stance, nitrate of nickel and then carefully reducing. 1

In the reactions contemplated in the present invention, hydrogen cannot be used as the inert gas since it is condensed by the,

catalytic metals and then reacts. Saturated hydrocarbon gases other than that intended to be produced may be employed; but carbon dioxid, nitrogen or steam are the best agents. Products of the combustion offuel may be used.

The same expedient of dilution with an inert gas may be employed in making useful products by the direct condensation of acetylene, ethylene, the diolefins and others of the highly reactive unsaturated endothermically constituted hydrocarbon gases and vapors. As stated, these bodies in the absence of hydrogen or other reactive gases nevertheless undergo mternal changes on contact with nickel and other catalytic bod-, ies; changes which are apt to become violent and uncontrollable. ethylene are unsaturated compounds of en- 'dothermic eonstitution capable of condens- Acetylene and ing and polymerizing and of breaking down the influence of catalysts. Acetylene has a strong tendency to condensation into benaltogether with liberation of heat under i -'a desired point by simply controlling the i a catalyst it should vacuum. In preparing reduce gas; and ing gas.

I catalyst, the

to the time of carbon compounds, which temperature of the catalyst at a suitable point while preventing violent local actions by dilution.

to beginning work with be freed from adsorbed gas or by a nickel, for reduced from In'all cases, prior gases by a'current of inert example, the metal is usually 'the oxid with hydrogen or other reducing left charged with such reduc- 1s If a reaction mixture be now introduced into contactwith it, the adsorbed hydrogen or other reducing gas at once becomes active and intense loc'a tem eratures maybe induced.- After reduction, t erefore, it is always better to ass an indifferent gas, such as carbon dioxid, steam or nitrogen over the metal; or to cool in a vacuum.

What we claim is: 1. The process of formin unsaturated carbon compounds by additive reaction which comprises, forming a dilute gaseous mixture of an unsaturated carbon compound with the gaseous form of a substance with which it will react to forman additive product, and passing the dilute mixture over a diluent being 'nert in the reaction, and present in such quantity relative exposure to the catalyst as to inhibit the formation of a saturated carbon compound. Y v

2. The process of forming unsaturated comprises forming a dilute gaseous mixture of an unsat urated carbon compound with a gaseous form of a substance with which'it will react to form an additive compound, and passing the dilutedmixture over a temperature controlled catalyst, the diluent being inert 1n the reaction and present in such quantity relative to. the time ofexposure to the catalyst and tothe temperature thereof as to inhibit tha formation of a saturated carbon oun 3-. In the catalytic treatment of acetylene in an exothermic reaction the process of re- -stra1ning,.the exothermic reac 1on which comprisesadding a diluent gas inert to at least one of the reacting substances and passing thediluted gaseous mixture over a catalyst. I

4. In the catalytic treatment of acetylene in an exothermic reaction the process of restraining the exothermic reaction which comprises adding a diluent gas inert to at least one of the reacting substances and pass-' ing the diluted gaseous mixture over a temperature-controlled catalyst.

5. In the catalytic treatment of acetylene in an exothermic reaction the process of restraining the exothermic reaction which comprises adding a diluent gas inert to at least straining the exothermic reaction which comprises adding a diluent gas inert to at least one of the reacting substances and passing the diluted gaseous mixture over a catalyst comprising reduced nickel.

7. In the manufacture of ethylene, the process which comprises adding a diluent inert gas to a mixture of substantially equal volumesof acetylene and hydrogen and passingtthe diluted gaseous mixture over a catays I 8'. In the manufacture of ethylene, the

rocess which comprises adding a diluent mert gas to a mixture of substantially equal volumes of acetylene and hydrogeri' and passing the diluted gaseous mixture over a temperature-controlled catalyst.

'9. In the manufacture of ethylene, the process which comprises adding carbon dioxid as a diluent gas to a mixture of substantiallyequal volumes of acetylene and hydrogen and passing the diluted gaseous mixture over a catalyst.

10. In the manufacture of ethylene, the process which comprises adding carbon dioxid as a diluent gas to a mixture of substantially equal volumes of acetylene and hydrogen and passing the diluted gaseous process which comprises adding carbon d1- oxid as a diluent gas to a mixture of substantially'equal proportions of acetylene and hydrogen andpassing the mixture over a catalyst comprising reduced nickel.

13. In the manufacture of ethylene gas from acetylene and hydrogen in the presence of a catalyst the admixture of ameutral diluent gas to at least one of the reacting substances in predetermined proportion to retard, regulate and control the-velocity of reaction. I a I 14. In the manufacture of ethylene gas from acetylene and hydrogen in the presence of a catalyst the admixture of carbon dioxid in predetermined proportion toretard, regulate and control the velocity of reaction.

15. In the addition of hydrogen to unsaturated hydrocarbons in gaseous form, the

process which comprises freeing a catalyst from adsorbed gases, and then passing the reacting hydrocarbons and hydro en over saidcittalyst in the presence of a di uent gas inert in the reaction.

5 16. In the manufacture of ethylene gas from acetylene and hydrogen in the presence of a catalystthe mixture of acetylene and hydrogen with carbon dioxid in predetermined proportion to'retard, regulate and. 10 control the velocity of reaction, the removing of the ethylene, and the recovermg of 

